Question

Find the sum of the arithmetic series.

(Question will be posted below.)

Answer 1

\[\large \sum_{n=1}^{5}(2n -3)\]

Answer 2

@rebeccaxhawaii

Answer 3

okay so there a_1=(2(1)-3) and a_5=(2(5)-3)

Answer 4

a_1 = -1
a_5 = 7

Answer 5

the common difference would be 2 right?

Answer 6

correct so plug it in to \[s_n=\frac{ n }{ 2 }[a_1+a_n]\]

Answer 7

n=5

Answer 8

why would n = 5?

Answer 9

this shows there are 5 terms in your sequence